Textile bobbin



Aug. 28, 1962 R. ATwooD ETAL TEXTILE BOBBIN Filed June 18, 1958 NVENTOR S mm zfxm/ o NY Unite te This invention relates to textile bobbins and more particularly to means for securing the inner end (socalled transfer tab) of a filament or thread to the bobbin.

Various transfer tail holding means have been proposed, `but having obvious disadvantages in liability of damage, and expense as well Ias the disadvantage always present in the addition of an extra element or operation in the construction or use of a bobbin.

It is the object of the present invention to provide a transfer tail locking device which involves substantially no added expense or added parts to the bobbin construction Iand which grips the thread securely and with a minimum of lost time in inserting the thread.

A bobbin embodying the invention in a preferred form will now -be described with reference to the accompanying drawing and the features forming the invention will then be pointed out in the appended claims.

In the drawings:

FIG. l is a side elevation of a bobbin embodying the invention in a preferred form;

FIG. 2 is an axial section on the line 2 2 of FIG. 1;

FIG. 3 is `a side elevation showing a modification of the bobbin of FIG. l;

FIG. 4 yis an axial section on the line 4-4 of FIG. 3; and

FIGS. 5 and 6 are fragmentary views similar to FIGS. 1 and 3, respectively, showing a modification.

The bobbin generally may be constructed in any desired manner and provided with bearings and end fittings according to the particular class of service for which it is intended. There is shown by way of definiteness of example in the drawing, la bobbin comprising a tubular metal barrel element 1 with end fittings 2 and 3 which may be nylon or other plastic. The structure is similar to the bobbin structure disclosed in Atwood and LAllemand application, Serial No. 494,405, filed March 15, 1955, now Patent No. 2,953,317 for Spool and will not be further described herein. A tubular plastic cover 4 is applied to the barrel 1, being curled over and into the top end fitting 2 as shown at 5 to form a rounded end and extending down beyond the metal over the circumference of the end fitting 3, which fitting has an outer surface flush with the metal barrel 1 or of `slightly greater diameter.

The lower end of the tubular cover 4 is generally squared off as along the line 6 but is cut with rounded tabs 7, as indicated. There may be any desired number of these tabs, and in particular two such tabs spaced apart 180 may be provided as in the construction shown. Ordinarily, where a plurality of tabs are provided they will Ibe spaced symmetrically around the bobbin. By reason of the tubular or cylindrical form of the tab 7, it possesses considerable stiffness and will hug the surface of the end fitting 6 which forms the end of the barrel structure, since any motion away from the surface of the end tting requires a liattening or buckling of this curled element. In the particular bobbin shown by way of example, the plastic covering 4 is of styrene acrylonitrile copolymer, such as marketed under the name Kralastic, but the construction of the invention may be used with practically any plastic or other tubular covering possessing reasonable properties as to stiffness or elasticity. The t-ail T is inserted under the tab 7, pulling it across the surface of the end 6 and against the end of the tab 7,

arent C ICC which causes the thread to slide under the tab, where it is then held with a secure frictional grip against any tension encountered in use but may be extracted by pulling out `from under the tab whenever desired. As will be understood, the tail T forms the end of the inside layer of filament or yarn Wound on the bobbin, as indicated in dot-dash outline in FIG. l, and forms part of a number of turns placed on the bobbin end in transferring the Wind from the waste spool to `the bobbin in the usual way. The construction of the invention may, however, be used for securing the end of a yarn to a bobbin for any other desired reason.

The form of tab m-ay be varied -and one such variation which has Ibeen found useful is shown in FIGS. 3 and 4. In that case, the lower end of the cover 4 is generally squared off at 6', as before, Iand is provided with three axially extending tabs 7 which have a generally rectangular form with so-mewhat rounded corners 8. In this construction, the tail T may be inserted first under either corner 8 and then tensioned to force it under the entire tab as shown. This type of t-ab may have somewhat greater circumferential extent and somewhat greater stili.- ness and, accordingly, exerts somewhat more holding force than the rounded tab of FIG. l.

The tabs 7 and 7 are unitary parts of the tubular covering elements 4 and 4 and may be formed by cutting olf extruded tubing into the shapes indicated. It will be apparent that practically no additional cost or complication of manufacture is involved in producing the construction of the present invention and that an exceptionally convenient and fool-proof means for holding the thread has been provided.

As stated above, the number of tabs is not critical and may be varied to suit the preference and convenience of the user. By varying the peripheral or circumferential dimension of the tab, its holding force may be varied. In general, the stiffer the material of the cover 4, the narrower the tab may be made and its width (circumferentially) may be increased beyond that indicated yin the drawings (about in a 1% diameter bobbin) where weaker materials than Kralastic are used for the cover. With respect to length of tab (axially) i/l or so is sufficient in most cases, and this length is not critical. Enough barrel surface beyond the tab should be left, however, to permit stretching the tail T around the end below the tab.

Since the resistance of the tab to lifting is principally yby reason of its curvature, it will be apparent that the rounded tip of the tab of FIG. 1 will, since it is narrower (peripherally) than the tab in general, lift without too much resistance and permit the wedging of the yarn or thread underneath it. The yarn or thread once having been started under the tab may readily be tensioned and forced upwardly to a point suiciently near the base of the tab so that it is securely held. A similar effect occurs at each corner of the rectangular tab of FIGS. 3 and 4.

To provide greater ease of insertion of the yarn tail under the tab, particularly where stiffer covers 4 or 4 are used, the barrel end may be tapered somewhat as shown in FIGS. 5 and 6. As there shown, an end 3', otherwise similar to the end 3 previously described, has a taper from line 9, about the middle of the tab 7 or 7', providing a separation between the top of the tube and the member 3 to facilitate insertion of the yarn. The yarn may be drawn up under the tab so as to be held against the untapered part of the `barrel end, as before. As will be understood, the extent of the taper shown in the drawing is somewhat exaggerated for purposes of illustration, a total taper measured in thousands of an inch being ordinarily sufficient.

What is claimed is: 1. A textile bobbin comprising a generally cylindrical barrel structure and a flexible tubular cover thereon, the cover extending over substantially the entire thread carrying surface of the bobbin and having at one end a peripherally limited tab portion extending beyond the end of the tubular cover :generally and lying against the surface of tthe barrel structure which also extends 'beyond the tubular cover, whereby the thread end may be inserted under the said tab portion and frictionally held thereby against the surface of the barrel structure.

2. A textile bobbin comprising a generally cylindrical barrel structure and a .flexible tubular cover thereon, the cover extending over substantially the entire thread carrying surface of the bobbin and having at one end a peripherally limited tab portion extending beyond the end of the tubular cover generally and lying against the surface of ,the barrel structure which also extends beyond the tubular cover, whereby the thread end may be inserted under the said tab portion and frictionally held thereby against the surface of the barrel structure, the said tab portion forming a cylindrical continuation of the cover and having sufficient width to hug the barrel structure surface.

3. A textile bobbin comprising a generally cylindrical barrel structure' and a tubular cover thereon, the cover extending over substantially the entire thread carrying surface of the bob-bin and having at one end a peripheral- 1y limited tab portion extending beyond the end of the tubular cover generally and lying against the surface of the barrel structure which also extends beyond the tubular cover, the said tab portion being curved like the cover generally and hugging the barrel structure surface, and

the `barrel structure being tapered slightly under the end of the tab portion, whereby the ,thread end may be inserted under the said tab portion and frictionally held thereby against the surface of the barrel structure.

4. A textile bobbin comprising a generally cylindrical 4 barrel structure including a barrel element extending throughout the thread supporting portion of the bobbin and a bobbin end fixed to the barrel and having a surface flush therewith but beyond the thread carrying portion of the bobbin, a tubular cover `on the barrel, the said cover covering substantially the entire thread supporting portion of the bobbin, extending part way over the said flush surface of the end and having a peripherally limited tab portion extending further over the said flush surface but not to the end thereof, whereby the thread end may be inserted under the said tab portion and frictionally 'held thereby against the said flush surface.

5. A textile bobbin according to claim 4, in which the said tubular cover has a plurality of such tab portions spaced apart circumferentially, whereby the thread may be tensioned between the said tab portions for insertion under one of them.

6. A textile bobbin according to claim 4, in which the said bobbin end has a taper from a line about midway of the said tab portion to the end of the bobbin for facilitating insertion of a thread end under the tab portion.

References Cited in the file of this patent UNITED STATES PATENTS 

